Semiconductor unit package and semiconductor unit packaging method, and encapsulant for use in semiconductor unit packaging

摘要

An improved semiconductor unit package method is disclosed. This method is implemented by a semiconductor device having an electrode pad, a substrate having a terminal electrode, a bump electrode formed on the electrode pad, a conductive adhesion layer with flexibility, and an encapsulating layer formed by curing a composition the viscosity and thixotropy index of which are below 100 Pa . s and below 1.1, respectively. Such a composition essentially consists of (A) a resin binder that contains, for example, a polyepoxide, an acid anhydride, and a rheology modifier and (B) a filler. The rheology modifier is one capable of impeding interaction between a free acid contained in the acid anhydride and a polar group at the surface of the filler. An encapsulant with improved flowability is used, so that the encapsulant readily flows and spreads to fill a gap between the semiconductor device and the substrate with no air bubbles. This achieves semiconductor unit packages with high reliability and productivity.